Stenus jiulongshanus Tang & Puthz

Liang, Tang, Zhao, Yun-Long & Puthz, Volker, 2008, Six new Stenus species of the cirrus group (Coleoptera, Staphylinidae) from China with a key to species of the group, Zootaxa 1745, pp. 1-18 : 7-8

Stenus jiulongshanus Tang & Puthz , sp. nov.

( Figs. 3 , 16–19 )

Type material. Holotype: CHINA: Zhejiang Prov.: ɗ, Suichang County, Mt. Jiulongshan, alt. 500–700 m, 31.VII.2006, SHEN Shan-Jia & LI Jin-Wen leg. ( SHNU). Paratypes: CHINA: Zhejiang Prov.: 5ɗɗ, 5ΨΨ, same data as for the holotype (4ɗɗ, 4ΨΨ in SHNU, ɗ, Ψ in cPut).

Description. BL: 3.8–4.8 mm; FL: 1.9–2.1 mm.

Proportional measurements of holotype: HW: 38, PW: 30, PL: 31.5, EW: 35.5, EL: 36, SL: 25.

Brachypterous, blackish with some brownish tint, glossy, each elytron with small orange spot; forebody very coarsely, densely punctate, abdomen coarsely and moderately sparsely (anteriorly) to finely and very sparsely (posteriorly) punctate; pubescence very long, especially erect on abdomen. Antennae yellowish, club infuscate. Maxillary palpi yellowish. Legs yellowish red. Clypeus black, labrum brown, moderately densely pubescent.

Head 1.07 times as wide as elytra; clypeofrontal area densely punctate and pubescent; basiantennal tubercles small; interocular area with deep longitudinal furrows, median portion convex, extending to the level of inner eye margins; punctures round to elliptic, larger and sparser on median area than those near inner margins of eyes, diameter of large punctures about as wide as medial cross section of 2nd antennal segment, interstices between punctures smooth, distinctly smaller than half diameter of punctures, larger along midline. Antennae when reflexed slightly extending beyond posterior margin of pronotum; 3rd to 8th segments much narrower than 2nd; 9th to 11th gradually broadened, forming loose club; relative length of segments from base to apex as 9.0: 5.5: 15.0: 7.5: 7.0: 6.0: 5.5: 4.0: 4.5: 5.0: 6.0. Paraglossae oval.

Pronotum 1.05 times as long as wide, 0.85 times as wide as elytra, widest near middle and constricted at base; disk uneven, with faint median longitudinal furrow which is about 2/3 the length of pronotum, two impressions in anterior half, two impressions in about middle and two impressions in posterior half; punctures round, some of them confluent, different in size, diameter of large punctures about as wide as medial cross section of 2nd antennal segment, interstices smooth, distinctly smaller than half diameter of punctures.

Elytra nearly as long as wide, distinctly constricted at base, lateral margins gently divergent posteriad; posterior conjoint margins roundly and distinctly emarginate at middle; disk uneven with distinct humeral impression and faint sutural impression; punctures and interstices similar to those on pronotum. Lateral elytral spot variable in size, 1/4 to 1/3 as long as and 1/4 to 1/3 as broad as the respective elytron.

Legs elongate, hind tarsi 0.77 times as long as hind tibiae, 4th tarsomeres strongly bilobed.

Abdomen cylindrical; paratergites very narrow and punctate, present only in 3rd segment; punctures round to elliptic, gradually becoming smaller posteriad, each puncture with long and suberect seta, interstices smooth, varied from smaller to larger than diameter of punctures.

Male. Sixth sternite ( Fig. 16 ) with shallow emargination at middle of posterior margin; 7th sternite ( Fig. 16 ) impressed at posteromedian part with an emargination along posterior margin of impressed area; 8th sternite ( Fig. 16 ) with distinct emargination at middle of posterior margin; 9th sternite ( Fig. 17 ) with pair of posterolateral projections which are acutely pointed apicad, posterior margin serrately emarginate. Aedeagus ( Fig. 18 ) with median lobe subparallel at base and tapering apicad at about basal 1/2, apical sclerotized area with cuspidate projection at apex, expulsion clasp ( Fig. 19 ) strongly sclerotized; parameres almost straight, distinctly longer than median lobe, each with about 23–31 setae on apico-internal margins.

Female. Abdomen broader than that in male; 8th sternite with posterior margin weakly pointed at middle. (An illustration of the spermatheca is not given here, as it would be inaccurate based on immature females.)

Variability. Body size, size of elytral spots and number of confluent punctures on forebody are somewhat different in the type series.

Remarks. This new species is similar to S. cooterianus Puthz, 2003 described from Jiangxi Province, but may be distinguished by slightly less coarse, denser and less regular punctation on pronotum and elytra, larger body size and different sexual characters.

Distribution. China (Zhejiang Province).

Etymology. The specific name is derived from “Jiulongshan”, the type locality of this species.

Figures

FIGURES 1 – 6. Stenus cirrus group, habitus. 1 — S. zhulilongi sp. nov., female; 2 — S. lijinweni sp. nov., male; 3 — S. jiulongshanus sp. nov., male; 4 — S. shenshanjiai sp. nov., male; 5, S. — flammeus sp. nov., male; 6 — S. bostrychus sp. nov., male. Scale bars 1 mm.

FIGURES 16 – 19. Details of Stenus jiulongshanus sp. nov. 16 — male 6 th – 8 th sternites; 17 — male 9 th sternite; 18 — aedeagus in ventral view; 19 — expulsion clasp of aedeagus. Scale bars 0.25 mm.